Add your HEIC file
Drop one or more .heic files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Converting a .heic image to .pgm re-encodes the pixels for a different balance of size, quality, and support. Free, private, and validated — the file never leaves your browser.
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.Converting a .heic image to .pgm re-encodes the pixels for a different balance of size, quality, and support. A .heic file contains imagery compressed with the HEVC (H.265) video codec inside the HEIF container — it is the specific HEVC-coded flavor of HEIF. Apple made it the default camera format on iPhone, so most .heic files people encounter are iPhone photos that roughly halve the storage of equivalent JPEGs.
A .pgm file is a Portable Graymap: a single-channel greyscale image storing one intensity value per pixel, with the maximum value declared in the header. It is the middle rung of the Netpbm ladder — richer than a one-bit bitmap, simpler than a colour pixmap. For this route the practical draw is raw samples in a declared range — no codec, no colour management, nothing to misinterpret and supports 16-bit depth, which most consumer formats do not — balanced against uncompressed, so files are large relative to PNG for the same data, which is worth knowing before you commit a large batch.
The practical trigger for this conversion is usually a mismatch: with .heic, hEVC patent licensing means Windows users must install a codec (historically a paid $0.99 extension) to view files. Switching to .pgm buys you raw samples in a declared range — no codec, no colour management, nothing to misinterpret, which is why it is the better fit for machine vision and image-processing pipelines that operate on intensity alone. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
| Aspect | HEIC image (.heic) | Portable graymap (.pgm) |
|---|---|---|
| Format type | Lossy — discards detail it judges invisible to shrink files | Lossless — every pixel or sample is preserved exactly |
| How it stores data | pixels are HEVC intra-coded, commonly at 10-bit depth on recent iPhones | p2 stores samples as whitespace-separated ASCII integers; P5 stores them as raw bytes |
| Strongest at | default photo capture on iPhone and iPad, halving camera roll storage | machine vision and image-processing pipelines that operate on intensity alone |
| Weak spot | hEVC patent licensing means Windows users must install a codec (historically a paid $0.99 extension) to view files | uncompressed, so files are large relative to PNG for the same data |
| Metadata | full EXIF (including GPS and orientation) and XMP are carried as container-level metadata items, and Apple additionally embeds depth and gain-map auxiliary data that most converters discard | none beyond header comments. No colour profile, no EXIF, no acquisition metadata — anything an instrument recorded alongside the pixels has to travel in a separate file |
Drop one or more .heic files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Select .pgm in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if PGM is selectable, the route is real and validated.
Press Convert. Decoding and re-encoding happen on your device using the browser's native image pipeline and hand-tuned encoders.
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid PGM file. Outputs keep the original filename with the .pgm extension.
No new loss is introduced — since heic is lossy-oriented and pgm is lossless-oriented, everything the .heic file still contains is carried over exactly. What was already discarded by the original lossy encode cannot be recovered, though; converting to .pgm does not "restore" quality.
Yes — the .heic file is processed inside your browser tab and never uploaded. Decoding and re-encoding happen on your device using the browser's native image pipeline and hand-tuned encoders. Close the tab and the file is gone from memory.
Standard in scientific and machine-vision toolchains — OpenCV, ImageMagick, MATLAB and Netpbm all read it — and absent from consumer software and browsers. Novus Convert decodes both ASCII and binary PGM locally, honours the declared maximum value when scaling to 8-bit output, and converts to the standard raster formats.
Larger, sometimes much larger. A lossless .pgm must store every pixel or sample the decoder produced, without the perceptual shortcuts .heic used. Use this route for editing headroom, not for saving space.
In .heic, full EXIF (including GPS and orientation) and XMP are carried as container-level metadata items, and Apple additionally embeds depth and gain-map auxiliary data that most converters discard. Re-encoding through the browser pipeline does not carry embedded metadata into the output, which doubles as a privacy scrub — check the exported file if you specifically need tags preserved.